如何将变量名作为参数传递给函数？

Question

首先，我不是这个意思：

int Value = 3;
SomeFunction(3); 
SomeFunction(Value);

相反，我的意思是：

Editor.h：（**不是**

#include Foo

）

#include "GameObjectFactory.h"

int main()
{
Object * Foo = SpawnGameObject("Foo");
printf("%i ", value);
SomeFunction(Foo, "value", "3"); // <- This is what I want to do!
printf("%i", value);

// Foo->value = 3;
// Does not work, not #included
}

结果：

0 3

你 CANNOT

#include Foo

：如果客户创建一个新的类 Bar，他们可能会给它一个

string name

，它不能在只处理 Foo 的

int value

变量的编辑器代码中编辑。这意味着客户端在添加新类时必须更改编辑器代码。 类必须按原样工作，不更改任何其他代码文件

正因为如此，

SomeFunction()

应该能够在instance-to-instance 的基础上更改客户给它的any any 变量：一个客户可能有两个值为 2 的 Foos，和三个值为 1。在这种情况下，编辑器应该能够生成五个 Foos 并根据例如它读取的文本文件为它们赋予适当的值。

我知道这可能需要大量重新格式化。没事儿。只要能这样就好了

上例相关代码：

Foo类：

#include "GameObjectFactory.h"

ENGINE_SPAWNABLE(Foo);
class Foo : GameObject
{
    int value = 0;
};

GameObjectFactory.h：（基本工厂实现）

#pragma once

#include <functional>
#include <string>
#include <unordered_map>

#include "Object.h"

// Allows GameObject to be spawnable through SpawnGameObject. No need to use this if the class is never spawned through the engine
#define ENGINE_SPAWNABLE(CLASSNAME) \
class CLASSNAME; \
static bool CLASSNAME##Registered \
= (GameObjectFactory::GetInstance().GetGameObjectRegistry()[#CLASSNAME] = &GameObjectFactory::SpawnObject<CLASSNAME>, true)
// Registers the class with the factory's registry, and connects that to a templated SpawnGameObject function

// Spawns a class of selected name
#define SpawnGameObject GameObjectFactory::GetInstance().SpawnGameObjectByName

// Singleton game object factory
class GameObjectFactory
{
public:
    // Gets instance of the simpleton
    static GameObjectFactory& GetInstance()
    {
        static GameObjectFactory Instance;
        return Instance;
    }

    // A templated function to spawn any registered GameObject
    template <typename TObject>
    static Object* SpawnObject()
    {
        return new TObject();
    }

    // A factory function that spawns an object of the specified class name
    Object* SpawnGameObjectByName(const std::string& Name);

    std::unordered_map<std::string, std::function<Object*()>> &GetGameObjectRegistry(); // Returns the Registry of class names

private:
    std::unordered_map<std::string, std::function<Object*()>> Registry; // Registry that maps class names to factory functions
};